Abs moulding material with improved workability and a high lustre

ABSTRACT

The invention relates to ABS moulding compositions, wherein the graft rubber polymers contain 3 butadiene polymer latices of defined particle size, particle size distribution and gel content, and wherein at least one polybutadiene latex has been produced by seed polymerisation.

[0001] ABS moulding compositions have already been used for many yearsin large amounts as thermoplastic resins for producing all types ofmoulded parts. In this connection the properties of these resins may bevaried within wide ranges.

[0002] In order to produce large-area parts, in particular housingparts, ABS polymers are required that are characterised by a very goodprocessing performance, in particular by a very high thermoplasticflowability, and that can be used to produce moulded parts having a veryhigh surface gloss. In this connection the other properties (e.g.toughness, modulus of elasticity) must not be negatively influenced.

[0003] Attempts have been made using emulsion polymerisation technologyto produce products having the required properties by combined use ofvarious graft rubber components in a thermoplastic resin matrix.

[0004] Thus, DE-A 24 20 357 and DE-A 24 20 358 for example describethermoplastic moulding compositions of the ABS type having hightoughness, high surface gloss and easier processability by combining acoarsely particulate graft rubber with a finely particulate graftrubber, wherein the weight ratios of styrene to acrylonitrile in thegraft rubbers and in the matrix resin must have special values.

[0005] A disadvantage of such moulding compositions of the ABS type isthat two separately produced graft rubber polymers are required. Also,the flow properties do not meet the requirements of modem processingtechnology.

[0006] EP-A 470 229, EP-A 473 400 and WO 91/13118 disclose thatimpact-resistant, high-gloss thermoplastic resins can be produced bycombining a graft polymer

[0007] having a low rubber content and small particle diameter with agraft polymer having a high rubber content and relatively large particlediameter.

[0008] The disadvantage of these products is the not always sufficientthermoplastic flowability as well as the necessity for two separategraft polymerisation stages.

[0009] DE-A 41 13 326 describes thermoplastic moulding compositions withtwo different graft products, wherein the rubber content of the graftrubbers are in each case at most 30 wt. %. Accordingly it is necessaryto use relatively high amounts of graft rubbers, which means that thethermoplastic flowability can be varied only within narrow ranges.Furthermore, the gloss values that can be achieved are unsatisfactoryand here too two separate graft polymerisation reactions are necessary.

[0010] Attempts have also been made by using mixtures of two rubberlatices as grafting bases to synthesise graft rubbers for the productionof improved ABS products.

[0011] Thus for example EP-A 288 298 describes the production ofproducts with a finely particulate and a more coarsely particulaterubber latex as grafting bases, though only grafting rubbers with lowrubber contents of around 40% are described. The thermoplastic resinsproduced therefrom have an unsatisfactory processability however onaccount of the poor thermoplastic flowability; furthermore resincomponents with high acrylonitrile contents must be used, which normallyleads to discoloration of the ABS products.

[0012] EP-A 745 624 describes the use of two rubber latices with definedparticle size distribution widths for producing ABS mouldingcompositions without any deepening of the colour shade in moulded partswith rib structures. These products however are characterised by a poorrelationship between toughness and thermoplastic processability(flowability).

[0013] The object therefore existed of providing thermoplastic mouldingcompositions of the ABS type that do not exhibit the aforementioneddisadvantages, that have a very good thermoplastic processability, andthat can be used to make moulded parts having a very high surface gloss.In this connection the ABS moulding compositions should preferablycontain a graft rubber product produced in a single process step,wherein the said graft rubber polymer should have rubber contents ofgreater than 50 wt. %, preferably above 55 wt. %.

[0014] The present invention accordingly provides polymer compositionscontaining

[0015] I) a graft rubber polymer that can be obtained by emulsionpolymerisation of styrene and acrylonitrile in a weight ratio of 95:5 to50:50, wherein styrene and/or acrylonitrile can be wholly or partiallyreplaced by α-methylstyrene, methyl methacrylate or N-phenylmaleimide ormixtures thereof, in the presence of a mixture of a butadiene polymerlatex (A) with a mean particle diameter d₅₀≦250 nm, preferably 100 to240 nm, particularly preferably 130 to 230 nm and most particularlypreferably 150 to 220 nm and a particle size distribution width(measured as d₉₀-d₁₀ from the integral particle size distribution) of 20to 80 nm, preferably 30 to 60 nm, and a gel content of 30 to 95 wt. %,preferably 40 to 90 wt. % and particularly preferably 50 to 85 wt. %,preferably obtained by seed polymerisation using a seed latex with amean particle diameter d₅₀ of 10 to 100 nm, preferably 20 to 90 nm andparticularly preferably 30 to 80 nm, a butadiene polymer latex (B) witha mean particle diameter d₅₀>250 nm to 350 nm, preferably 260 to 340 nmand particularly preferably 270 to 320 nm, a particle size distributionwidth (measured as d₉₀-d₁₀ from the integral particle size distribution)of 30 to 100 nm, preferably 40 to 80 nm, and a gel content of 30 to 80wt. %, preferably 40 to 75 wt. % and particularly preferably 45 to 70wt. %, preferably obtained by seed polymerisation using a seed latexwith a mean particle diameter d₅₀ of 30 to 150 nm, preferably 35 to 140nm and particularly preferably 4 0 to 130 nm, most particularlypreferably using the same seed latex as in the production of thepolybutadiene polymer latex (A), and a butadiene polymer latex (C) witha mean particle diameter d₅₀>350 nm, preferably 360 to 450 nm,particularly preferably 370 to 440 nm and most particularly preferably375 to 430 nm, a particle size distribution width (measured as d₉₀-d₁₀from the integral particle size distribution) of 40 to 150 nm,preferably 50 to 100 nm, and a gel content of 50 to 95 wt. %, preferably55 to 90 wt. % and particularly preferably 60 to 85 wt. %, preferablyobtained by seed polymerisation using a seed latex with a mean particlediameter d₅₀ of 100 to 250 nm, preferably 120 to 240 nm and particularlypreferably 150 to 220 nm, most particularly preferably using thebutadiene polymer latex (A) as seed latex, wherein the butadiene polymerlatices in each case contain 0 to 50 wt. % of a further vinyl monomerincorporated by copolymerisation and wherein the weight ratio of thegraft monomers that are used to the butadiene polymers that are used is5:95 to 70:30, preferably 10:90 to 60:40, and particularly preferably20:80 to 50:50, and

[0016] II) at least one rubber-free copolymer of styrene andacrylonitrile in a weight ratio of 95:5 to 50:50, wherein styrene and/oracrylonitrile can be wholly or partially replaced by α-methylstyrene,methyl methacrylate or N-phenylmaleimide or mixtures thereof,

[0017] wherein at least one latex selected from the butadiene polymerlatices (A), (B) and (C), preferably two latices selected from thebutadiene polymer latices (A), (B) and (C), and particularly preferablyall three butadiene polymer latices (A), (B) and (C) is/are produced byseed polymerisation.

[0018] The butadiene polymer latices (A), (B) and (C) may in principlebe employed in arbitrary amounts in the production of the graft rubberpolymer (I).

[0019] The butadiene polymer latices (A), (B) and (C) are preferablyused in the production of the graft rubber polymer (I) in amounts of 5to 70 wt. %, preferably 10 to 60 wt. % and particularly preferably 15 to50 wt. % of (A), 10 to 70 wt. %, preferably 15 to 60 wt. % andparticularly preferably 20 to 55 wt. % of (B), and 5 to 60 wt. %,preferably 7.5 to 50 wt. % and particularly preferably 10 to 45 wt. % of(C) (in each case referred to the respective solids content of thelatices).

[0020] In general the moulding compositions according to the inventionmay contain 1 to 60 parts by weight, preferably 5 to 50 parts by weightof (I), and 40 to 99 parts by weight, preferably 50 to 95 parts byweight of (II).

[0021] The invention furthermore provides a process for producing apolymer composition, wherein a graft rubber polymer that can be obtainedby emulsion polymerisation of styrene and acrylonitrile in a weightratio of 95:5 to 50:50, wherein styrene and/or acrylonitrile may bewholly or partially replaced by α-methylstyrene, methyl methacrylate orN-phenyl-maleimide or mixtures thereof, is produced in the presence of amixture of a butadiene polymer latex (A) with a mean particle diameterd₅₀<250 nm and a particle size distribution width (measured as d₉₀-d₁₀from the integral particle size distribution) of 20 to 80 nm, and a gelcontent of 30 to 95 wt. %, a butadiene polymer latex (B) with a meanparticle diameter d₅₀>250 to 350 nm, a particle size distribution width(measured as d₉₀-d₁₀ from the integral particle size distribution) of 30to 100 nm, and a gel content of 30 to 80 wt. %, and a butadiene polymerlatex (C) with a mean particle diameter d₅₀>350 nm, a particle sizedistribution width (measured as d₉₀-d₁₀ from the integral particle sizedistribution) of 40 to 150 nm, and a gel content of 50 to 95 wt. %,using at least one latex produced by seed polymerisation and selectedfrom the butadiene polymer latices (A), (B) and (C), wherein thebutadiene polymer latices in each case contain 0 to 50 wt. % of afurther vinyl monomer incorporated by copolymerisation and wherein theweight ratio of graft monomers that are used to butadiene polymers thatare used is 5:95 to 70:30, and the graft polymer is mixed with at leastone rubber-free copolymer of styrene and acrylonitrile in a weight ratioof 95:5 to 50:50, wherein styrene and/or acrylonitrile may be partiallyor wholly replaced by α-methylstyrene, methyl methacrylate orN-phenylmaleimide or mixtures thereof.

[0022] Furthermore the moulding compositions according to the inventionmay contain further rubber-free thermoplastic resins that are not builtup from vinyl monomers, wherein these thermoplastic resins are used inamounts of up to 1000 parts by weight, preferably up to 700 parts byweight and particularly preferably up to 500 parts by weight (in eachcase referred to 100 parts by weight of I+II).

[0023] The butadiene polymer latices (A), (B) and (C) may be produced byemulsion polymerisation of butadiene in a manner known per se (see forexample Houben-Weyl, Methoden der Organischen Chemie, MakromolekulareStoff, Part 1, p. 674 (1961), Thieme Verlag Stuttgart). As comonomersthere may be used up to 50 wt. % (referred to the total amount ofmonomers used in the production of the butadiene polymer) of one or moremonomers copolymerisable with butadiene.

[0024] Examples of such monomers include isoprene, chloroprene,acrylonitrile, styrene, α-methylstyrene, C₁-C₄-alkylstyrenes,C₁-C₈-alkyl acrylates, C₁-C₈-alkyl methacrylates, alkylene glycoldiacrylates, alkylene glycol dimethacrylates, divinyl benzene; butadieneis preferably used alone or mixed with up to 20 wt. %, preferably withup to 10 wt. %, of styrene and/or acrylonitrile.

[0025] The polymerisation is preferably carried out according to theso-called seed polymerisation technique, in which first of all a finelydivided polymer, preferably a butadiene polymer, is produced as seedlatex and is then further polymerised to form larger particles byfurther reaction with butadiene-containing monomers.

[0026] As seed latex polymers there are preferably used butadienepolymers such as e.g. polybutadiene, butadiene/styrene copolymers,butadiene/acrylonitrile copolymers, or polymers formed from theaforementioned monomers.

[0027] In principle other finely particulate latex polymers may also beused, for example polystyrene or styrene copolymers, poly(methylmethacrylate) or methyl methacrylate copolymers, as well as polymers ofother vinyl monomers.

[0028] Preferred seed latex polymers are butadiene latices.

[0029] In this connection a seed latex with a mean particle diameter d₅₀of 10 to 100 nm, preferably 20 to 90 nm and particularly preferably 30to 80 nm is used in the production of the butadiene polymer latex (A).

[0030] In the production of the butadiene polymer latex (B) a seed latexis used with a mean particle diameter d₅₀ of 30 to 150 nm, preferably 35to 140 nm and particularly preferably 40 to 130 nm, and it is mostparticularly preferred to use the same seed latex as is used in theproduction of the butadiene polymer latex (A).

[0031] In the production of the butadiene polymer latex (C) a seed latexis used with a mean particle diameter d₅₀ of 100 to 250 nm, preferably120 to 240 nm and particularly preferably 150 to 220 nm, and it is mostparticularly preferred to use the butadiene polymer latex (A) as seedlatex.

[0032] The seed latex polymers have a gel content of 10 to 95 wt. %,preferably 20 to 90 wt. % and particularly preferably 30 to 85 wt. %.

[0033] The butadiene polymer latex (A) has a mean particle diameterd₅₀<250 nm, preferably 100 to 240 nm, particularly preferably 130 to 230nm, and most particularly preferably 150 to 220 nm, a particle sizedistribution width (measured as d₅₀-d₁₀ from the integral particle sizedistribution) of 20 to 80 nm, preferably 30 to 60 nm, and a gel contentof 30 to 95 wt. %, preferably 40 to 90 wt. %, and particularlypreferably 50 to 85 wt. %

[0034] The butadiene polymer latex (B) has a mean particle diameter d₅₀of >250 nm to 350 nm, preferably 260 to 340 nm and particularlypreferably 270 to 320 nm, a particle size distribution width (measuredas d₅₀-d₁₀ from the integral particle size distribution) of 30 to 100nm, preferably 40 to 80 nm, and a gel content of 30 to 80 wt. %,preferably 40 to 75 wt. %, and particularly preferably 45 to 70 wt. %.

[0035] The butadiene polymer latex (C) has a mean particle diameter d₅₀of >350 nm, preferably 360 to 450 nm, particularly preferably 370 to 440nm, and most particularly preferably 375 to 430 nm, a particle sizedistribution width (measured as d₅₀-d₁₀ from the integral particle sizedistribution) of 40 to 150 nm, preferably 50 to 100 nm, and a gelcontent of 50 to 95 wt. %, preferably 55 to 90 wt. %, and particularlypreferably 60 to 85 wt. %.

[0036] The mean particle diameter d₅₀, as well as the d₁₀ values and d₉₀values, can be determined by ultracentrifugation measurements (see W.Scholtan, H. Lange: Kolloid Z. u. Z. Polymere 250, pp. 782 to 796(1972)), the specified values for the gel content referring to thedetermination by the wire cage method in toluene (see Houben-Weyl,Methoden der Organischen Chemie, Makromolkulare Stoffe, Part I, p. 307(1961), Thieme Verlag Stuttgart).

[0037] The gel contents of the butadiene polymer latices (A), (B) and(C) as well as of the seed polymer latices may in principle be adjustedin a manner known per se by employing suitable reaction conditions (e.g.high reaction temperature and/or polymerisation up to a high degree ofconversion as well as optionally the addition of crosslinking substancesin order to achieve a high gel content, or for example a low reactiontemperature and/or termination of the polymerisation reaction before toohigh a degree of crosslinking has occurred, as well as optionally theaddition of molecular weight regulators such as n-dodecyl mercaptan ort-dodecyl mercaptan in order to achieve a low gel content). Asemulsifiers there may be used conventional anionic emulsifiers such asalkyl sulfates, alkyl sulfonates, aralkyl sulfonates, soaps of saturatedor unsaturated fatty acids, as well as alkaline disproportionated orhydrogenated abietinic acid or tall oil acid, and preferably emulsifiershaving carboxyl groups are used (e.g. salts of C₁₀-C₁₈ fatty acids,disproportionated abietinic acid, emulsifiers according to DE-OS 36 39904 and DE-OS 39 13 509).

[0038] In order to achieve the effect according to the invention atleast one latex selected from the butadiene polymer latex components(A), (B) and (C), preferably two latices selected from the butadienepolymer latex components (A), (B) and (C), and particularly all threebutadiene polymer latex components (A), (B) and (C) must have beenproduced by seed polymerisation.

[0039] The graft polymerisation in the production of the graft polymerI) may be carried out according to any suitable methods, but ispreferably carried out in such a way that the monomer mixture iscontinuously added to the mixture of the butadiene polymer latices (A),(B) and (C), and is polymerised.

[0040] Special monomer/rubber ratios are preferably maintained duringthe polymerisation, and the monomers are added to the rubber in a mannerknown per se.

[0041] In order to produce the component I) according to the invention,preferably 15 to 50 parts by weight, particularly preferably 20 to 40parts by weight, of a mixture of styrene and acrylonitrile that mayoptionally contain up to 50 wt. % (referred to the total amount of themonomers employed in the graft polymerisation) of one or morecomonomers, are polymerised in the presence of preferably 50 to 85 partsby weight, particularly preferably 60 to 80 parts by weight (in eachcase referred to solids) of the butadiene polymer latex mixture of (A),(B) and (C).

[0042] The monomers used in the graft polymerisation are preferablymixtures of styrene and acrylonitrile in a weight ratio of 95:5 to50:50, particularly preferably in a weight ratio of 80:20 to 65:35,wherein styrene and/or acrylonitrile may be wholly or partially replacedby copolymerisable monomers, preferably by α-methylstyrene, methylmethacrylate or N-phenylmaleimide. In principle arbitrary furthercopolymerisable vinyl monomers may additionally be used in amounts of upto ca. 10 wt. % (referred to the total amount of the monomers).

[0043] In addition molecular weight regulators may be used in the graftpolymerisation, preferably in amounts of 0.01 to 2 wt. %, particularlypreferably in amounts of 0.05 to 1 wt. % (in each case referred to thetotal amount of monomers in the graft polymerisation stage).

[0044] Suitable molecular weight regulators are for example alkylmercaptans such as n-dodecyl mercaptan, t-dodecyl mercaptan; dimericα-methylstyrene; terpinolene.

[0045] Suitable initiators that may be used include inorganic andorganic peroxide, e.g. H₂O₂, di-tert.-butyl peroxide, cumenehydroperoxide, dicyclohexyl percarbonate, tert.-butyl hydroperoxide,p-menthane hydroperoxide, azo initiators such as azobisisobutyronitrile,persalts such as ammonium, sodium or potassium persulfate, potassiumperphosphate, sodium perborate, as well as redox systems. Redox systemsconsist as a rule of an organic oxidising agent and a reducing agent, inwhich connection heavy metal ions may in addition be present in thereaction medium (see Houben-Weyl, Methoden der Organischen Chemie, Vol.14/1, pp. 263 to 297).

[0046] The polymerisation temperature is in general 25° C. to 160° C.,preferably 40° C. to 90° C. Suitable emulsifiers are mentioned above.

[0047] The polymerisation may be carried out under normal temperatureconditions, i.e. isothermally; the graft polymerisation is howeverpreferably carried out so that the temperature difference between thestart and end of the reaction is at least 10° C., preferably at least15° C., and particularly preferably at least 20° C.

[0048] In order to produce the component I) according to the invention,the graft polymerisation may preferably be carried out by addition ofthe monomers in such a way that 55 to 90 wt. %, preferably 60 to 80 wt.% and particularly preferably 65 to 75 wt. % of the total amount ofmonomers used in the graft polymerisation are metered in during thefirst half of the overall time for metering in the monomers; theremaining proportion of the monomers is metered in within the secondhalf of the overall time for metering in the monomers.

[0049] As rubber-free copolymers II) there are preferably usedcopolymers of styrene and acrylonitrile in a weight ratio of 95:5 to50:50, in which connection styrene and/or acrylonitrile may be wholly orpartially replaced by α-methylstyrene, methyl methacrylate orN-phenylmaleimide.

[0050] Particularly preferred are copolymers II) containing proportionsof incorporated acrylonitrile units of <30 wt. %.

[0051] These copolymers preferably have mean molecular weights{overscore (M)}_(w) of 20,000 to 200,000 and intrinsic viscosities [η]of 20 to 110 ml/g (measured in dimethylformamide at 25° C.).

[0052] Details regarding the production of these resins are describedfor example in DE-A 2 420 358 and DE-A 2 724 360. Vinyl resins producedby bulk polymerisation or solution polymerisation have proved to beparticularly suitable. The copolymers may be added alone or as anarbitrary mixture.

[0053] Apart from using thermoplastic resins built up from vinylmonomers, it is also possible to use polycondensates, for examplearomatic polycarbonates, aromatic polyester carbonates, polyesters orpolyamides as rubber-free copolymer in the moulding compositionsaccording to the invention.

[0054] Suitable thermoplastic polycarbonates and polyester carbonatesare known (see for example DE-A 1 495 626, DE-A 2 232 877, DE-A 2 703376, DE-A 2 714 544, DE-A 3 000 610, DE-A 3 832 396, DE-A 3 077 934),which may be prepared for example by reacting diphenols of the formulae(III) and (IV)

[0055] in which

[0056] A denotes a single bond C₁-C₅-alkylene, C₂-C₅-alkylidene,C₅-C₆-cycloalkylidene, —O—, —S—, —SO—, —SO₂— or —CO—,

[0057] R⁵ and R⁶ independently of one another denote hydrogen, methyl orhalogen, in particular hydrogen, methyl, chlorine or bromine,

[0058] R¹ and R² independently of one another denote hydrogen, halogen,preferably chlorine or bromine, C₁-C₈-alkyl, preferably methyl, ethyl,C₅-C₆-cycloalkyl, preferably cyclohexyl, C₆-C₁₀-aryl, preferably phenyl,or C₇-C₁₂-aralkyl, preferably phenyl-C₁-C₄-alkyl, in particular benzyl,

[0059] m is an integer from 4 to 7, preferably 4 or 5,

[0060] n is 0 or 1,

[0061] R³ and R⁴ may be selected individually for each X andindependently of one another denote hydrogen or C₁-C₆-alkyl, and

[0062] X denotes carbon,

[0063] with carbonic acid halides, preferably phosgene, and/or witharomatic dicarboxylic acid dihalides, preferably benzenedicarboxylicacid dihalides, by phase boundary polycondensation, or with phosgene bypolycondensation in the homogeneous phase (so-called pyridine process),in which connection the molecular weight may be adjusted in a mannerknown per se by adding an appropriate amount of known chain terminators.

[0064] Suitable diphenols of the formulae (III) and (IV) are for examplehydroquinone, resorcinol, 4,4′-dihydroxydiphenyl,2,2-bis-(4-hydroxyphenyl)-propane,2,4-bis-(4-hydroxyphenyl)-2-methylbutane,2,2-bis-(4-hydroxy-3,5-dimethylphenyl)-propane,2,2-bis-(4-hydroxy-3,5-dichlorophenyl)-propane,2,2-bis-(4-hydroxy-3,5-dibromophenyl)-propane,1,1-bis-(4-hydroxyphenyl)-cyclohexane,1,1-bis-(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane,1,1-bis-(4-hydroxyphenyl)-3,3-dimethylcyclohexane,1,1-bis-(4-hydroxyphenyl)-3,3,5,5-tetramethylcyclohexane or1,1-bis-(4-hydroxyphenyl)-2,4,4,-trimethylcyclopentane.

[0065] Preferred diphenols of the formula (III) are2,2-bis-(4-hyroxyphenyl)-propane and1,1-bis-(4-hydroxyphenyl)-cyclohexane, and the preferred phenol of theformula (IV) is 1,1-bis-(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane.

[0066] Mixtures of diphenols may also be used.

[0067] Suitable chain terminators are for example phenol,p-tert.-butylphenol, long-chain alkyl phenols such as4-(1,3-tetramethylbutyl)phenol according to DE-A 2 842 005,monoalkylphenols, dialkylphenols having a total of 8 to 20 C atoms inthe alkyl substituents according to DE-A 3 506 472, such asp-nonylphenol, 2,5-di-tert.-butylphenol, p-tert.-octylphenol,p-dodecylphenol, 2-(3,5-dimethylheptyl)-phenol and4-(3,5-dimethylheptyl)-phenol. The necessary amount of chain terminatorsis generally 0.5 to 10 mole % referred to the sum of the diphenols (II)and (IV).

[0068] The suitable polycarbonates or polyester carbonates may be linearor branched; branched products are preferably obtained by incorporating0.05 to 2.0 mole %, referred to the sum of the diphenols employed, oftrifunctional or higher functionality compounds, for example thosehaving three or more than three phenolic OH groups.

[0069] The suitable polycarbonates or polyester carbonates may containaromatically bound halogen, preferably bromine and/or chlorine; however,they are preferably halogen-free.

[0070] The polycarbonates and polyester carbonates have mean molecularweights ({overscore (M)}_(w), weight average), determined for example byultracentrifugation or light scattering measurements, of 10,000 to200,000, preferably 20,000 to 80,000.

[0071] Suitable thermoplastic polyesters are preferably polyalkyleneterephthalates, i.e. reaction products of aromatic dicarboxylic acids ortheir reactive derivatives (e.g. dimethyl esters or anhydrides) withaliphatic, cycloaliphatic or arylaliphatic diols and mixtures of suchreaction products.

[0072] Preferred polyalkylene terephthalates can be prepared fromterephthalic acids (or their reactive derivatives) and aliphatic orcycloaliphatic diols with 2 to 10 C atoms according to known methods(Kunststoff-Handbuch, Vol. VIII, p. 695 ff, Carl Hanser Verlag, Munich1973).

[0073] In preferred polyalkylene terephthalates 80 to 100 mole %,preferably 90 to 100 mole % of the dicarboxylic acid residues areterephthalic acid residues, and 80 to 100 mole %, preferably 90 to 100mole % of the diol residues are ethylene glycol residues and/orbutanediol-1,4 residues.

[0074] The preferred polyalkylene terephthalates may in addition toethylene glycol residues or butanediol-1,4 residues also contain 0 to 20mole % of residues of other aliphatic diols with 3 to 12 C atoms orcycloaliphatic diols with 6 to 12 C atoms, for example residues ofpropanediol-1,3, 2-ethylpropanediol-1,3, neopentyl glycol,pentanediol-1,5, hexanediol-1,6,cyclohexanedimethanol-1,4,3-methylpentanediol-1,3 and-1,6,2-ethylhexanediol-1,3,2,2-diethylpropanediol-1,3,hexanediol-2,5,1,4-di(β-hydroxyethoxy)-benzene,2,2-bis-4-(hydroxycyclohexyl)-propane,2,4-dihydroxy-1,1,3,3-tetramethylcyclobutane,2,2-bis-(3-β-hydroxyethoxyphenyl)-propane and2,2-bis-(4-hydroxypropoxyphenyl)-propane (DE-OS 2 407 647, 2 407 776, 2715 932).

[0075] The polyalkylene terephthalates may be branched by incorporatingrelatively small amounts of trihydroxy or tetrahydroxy alcohols or3-basic or 4-basic carboxylic acids, such as as are described in DE-OS 1900 270 and in U.S. Pat. No. 3,692,744. Examples of preferred branchingagents are trimesic acid, trimellitic acid, trimethylolethane andtrimethylolpropane, and pentacrythritol. It is advisable to use not morethan 1 mole % of the branching agent, referred to the active component.

[0076] Particularly preferred are polyalkylene terephthalates that havebeen produced solely from terephthalic acid and its reactive derivatives(for example its dialkyl esters) and ethylene glycol and/orbutanediol-1,4, and mixtures of these polyalkylene terephthalates.

[0077] Preferred polyalkylene terephthalates are also copolyesters thathave been prepared from at least two of the abovementioned alcoholcomponents: particularly preferred copolyesters arepoly-(ethyleneglycolbutanediol-1,4)-terephthalates.

[0078] The preferably suitable polyalkylene terephthalates generallyhave an intrinsic viscosity of 0.4 to 1.5 dl/g, preferably 0.5 to 1.3dl/g, in particular 0.6 to 1.2 dl/g, measured in each case inphenol/o-dichlorobenzene (1:1 parts by weight) at 25° C.

[0079] Suitable polyamides are known homopolyamides, copolyamides andmixtures of these polyamides. These polyamides may be partiallycrystalline and/or amorphous.

[0080] Suitable partially crystalline polyamides are polyamide-6,polyamide-6,6, mixtures and corresponding copolymers prepared from thesecomponents. Also suitable are partially crystalline polyamides whoseacid component consists wholly or partially of terephthalic acid and/orisophthalic acid and/or cork acid and/or sebacic acid and/or azelaicacid and/or adipic acid and/or cyclohexanedicarboxylic acid, whosediamine component consists wholly or partially of m- and/or p-xylylenediamine and/or hexamethylene diamine and/or 2,2,4-trimethylhexamethylenediamine and/or 2,2,4-trimethylhexamethylene diamine and/or isophoronediamine, and whose composition is in principle known.

[0081] There may also be mentioned polyamides that have been producedwholly or partially from lactams with 7 to 12 C atoms in the ring,optionally with the co-use of one or more of the abovementioned startingcomponents.

[0082] Particularly preferred partially crystalline polyamides arepolyamide-6 and polyamide 6,6 and their mixtures. As amorphouspolyamides there may be used known products that are obtained bypolycondensation of diamines such as ethylene diamine, hexamethylenediamine, decamethylene diamine, 2,2,4- and/or2,4,4-trimethylhexamethylene diamine, m- and/or p-xylylene diamine,bis-(4-aminocyclohexyl)-methane, bis-(4-aminocyclohexyl)-propane,3,3′-dimethyl-4,4′-diamino-dicyclohexylmethane,3-aminomethyl-3,5,5,-trimethylcyclohexylamine, 2,5- and/or2,6-bis-(aminomethyl)-norbornane and/or 1,4-diaminomethylcyclohexanewith dicarboxylic acids such as oxalic acid, adipic acid, azelaic acid,decanedicarboxylic acid, heptadecanedicarboxylic acid, 2,2,4- and/or2,4,4-trimethyladipic acid, isophthalic acid and terephthalic acid.

[0083] Also suitable are copolymers obtained by polycondensation ofseveral monomers, as well as copolymers prepared with the addition ofaminocarboxylic acids such as ε-aminocaproic acid, ω-aminoundecanoicacid or ω-aminolauric acid or their lactams.

[0084] Particularly suitable amorphous polyamides are the polyamidesprepared from isophthalic acid, hexamethylene diamine and furtherdiamines such as 4,4′-diaminodicyclohexylmethane, isophorone diamine,2,2,4- and/or 2,4,4-trimethylhexamethylene diamine, 2,5- and/or2,6-bis-(aminomethyl)-nobornene; or from isophthalic acid,4,4′-diaminodicyclohexylmethane and ε-caprolactam; or from isophthalicacid, 3,3′-dimethyl-4,4′-diaminodicyclohexylmethane and laurinlactam; orfrom terephthalic acid and the isomeric mixture of 2,2,4- and/or2,4,4-trimethylhexamethylene diamine.

[0085] Instead of the pure 4,4′-diaminodicyclohexylmethane, mixtures ofthe positional isomeric diaminodicyclohexylmethanes consisting of thefollowing components may also be used

[0086] 70 to 99 mole % of the 4,4′-diamino isomer

[0087] 1 to 30 mole % of the 2,4′-diamino isomer

[0088] 0 to 2 mole % of the 2,2′-diamino isomer, and

[0089] optionally correspondingly higher condensed diamines that areobtained by hydrogenating industrial quality diaminodiphenylmethane. Theisophthalic acid may be replaced in an amount of up to 30% byterephthalic acid.

[0090] The polyamides preferably have a relative viscosity (measured ina 1 wt. % solution in m-cresol at 25° C.) of 2.0 to 5.0, particularlypreferably 2.5 to 4.0.

[0091] Preferred moulding compositions according to the inventioncontain 1 to 60 parts by weight, preferably 5 to 50 parts by weight ofgraft polymer component I) and 40 to 99 parts by weight, preferably 50to 95 parts by weight of rubber-free copolymer II).

[0092] The production of the moulding compositions according to theinvention is carried out by mixing the components I) and II) inconventional mixing units (preferably in multiple roll mills, mixingextruders or internal kneaders).

[0093] The invention furthermore provides a process for producing themoulding compositions according to the invention, wherein the componentsI) and II) are mixed and are compounded and extruded at elevatedtemperature, in general at temperatures from 150° C. to 300° C.

[0094] Necessary and/or advantageous additives, for exampleantioxidants, UV stabilisers, peroxide destroyers, antistatic agents,lubricating agents, mould release agents, flame protection agents,fillers or reinforcing materials (glass fibres, carbon fibres etc.) and,pigments may be added to the moulding compositions according to theinvention during the production, processing, further processing andfinal shaping stages.

[0095] The final shaping may be carried out in conventional processingunits, and includes for example processing by injection moulding, sheetextrusion optionally followed by heat forming, cold forming, extrusionof pipes and profiled sections, and calender processing.

[0096] In the following examples the specified parts are always parts byweight and the specified % are always wt. % unless otherwise stated.

EXAMPLES

[0097] Components

[0098] ABS Graft Polymer 1 (according to the invention)

[0099] 15 parts by weight (calculated as solids) of an anionicallyemulsified polybutadiene latex with a mean particle diameter d₅₀ of 191nm, a particle size distribution width d₉₀-d₁₀ of 42 nm and a gelcontent of 69 wt. % produced by free-radical seed polymerisation using apolybutadiene latex with a d₅₀ value of 46 nm, 30 parts by weight(calculated as solids) of an anionically emulsified polybutadiene latexwith a mean particle diameter d₅₀ of 297 nm, a particle sizedistribution width d₉₀-d₁₀ of 77 nm and a gel content of 61 wt. %produced by free-radical seed polymerisation using a polybutadiene latexwith a d₅₀ value of 125 nm as seed latex, and 15 parts by weight(calculated as solids) of an anionically emulsified polybutadiene latexwith a mean particle diameter d₅₀ of 422 nm, a particle sizedistribution width d₉₀-d₁₀ of 63 nm and a gel content of 80 wt. %produced by free-radical seed polymerisation using a polybutadiene latexwith a d₅₀ value of 125 nm as seed latex are adjusted with water to asolids content of ca. 20 wt. %, heated to 59° C., following which 0.5part by weight of potassium peroxodisulfate (dissolved in water) isadded.

[0100] 40 parts by weight of a mixture of 73 wt. % of styrene, 27 wt. %of acrylonitrile and 0.12 parts by weight of tert.-dodecyl mercaptan areuniformly metered in within 6 hours, and in parallel to this 1 part byweight (calculated as solids) of the sodium salt of a resin acid mixture(Dresinate 731, Abieta Chemie GmbH, Gersthofen, Germany, dissolved inalkaline adjusted water) is metered in over a period of 6 hours. Duringthe course of the 6 hours the reaction temperature is raised from 59° C.to 77° C. After a post-reaction time of 2 hours at 80° C. the graftlatex is coagulated after adding ca. 1.0 part by weight of a phenolicantioxidant, with a magnesium sulfate/acetic acid mixture and, afterwashing with water, the resulting moist powder is dried at 70° C.

[0101] ABS Graft Polymer 2 (according to the invention)

[0102] 15 parts by weight (calculated as solids) of an anionicallyemulsified polybutadiene latex with a mean particle diameter d₅₀ of 189nm, a particle size distribution width d₉₀-d₁₀ of 50 nm and a gelcontent of 76 wt. % produced by free-radical seed polymerisation using apolybutadiene latex with a d₅₀ of 46 nm as seed latex, 30 parts byweight (calculated as solids) of an anionically emulsified polybutadienelatex with a mean particle diameter d₅₀ of 285 nm, a particle sizedistribution width d₉₀-d₁₀ of 60 nm and a gel content of 67 wt. %produced by free-radical seed polymerisation using a polybutadiene latexwith a d₅₀ value of 119 nm as seed latex, and 15 parts by weight(calculated as solids) of an anionically emulsified polybutadiene latexwith a mean particle diameter d₅₀ of 399 nm, a particle sizedistribution width d₉₀-d₁₀ of 56 nm and a gel content of 85 wt. %produced by free-radical seed polymerisation using a polybutadiene latexwith a d₅₀ value of 189 nm as seed latex are adjusted with water to asolids content of ca. 20 wt. %, heated to 55° C., following which 0.5part by weight of potassium peroxodisulfate (dissolved in water) isadded.

[0103] 40 parts by weight of a mixture of 73 wt. % of styrene, 27 wt. %of acrylonitrile and 0.12 part by weight of tert.-dodecyl mercaptan areuniformly metered in within 5 hours, and in parallel to this 1 part byweight (calculated as solids) of the sodium salt of a resin acid mixture(Dresinate 731, Abieta Chemie GmbH, Gersthofen, Germany, dissolved inalkaline adjusted water) is metered in over a period of 5 hours. Duringthe course of the 5 hours the reaction temperature is raised from 55° C.to 80° C. After a post-reaction time of 2 hours at 80° C. the graftlatex is coagulated after adding ca. 1.0 part by weight of a phenolicantioxidant, with a magnesium sulfate/acetic acid mixture, and afterwashing with water the resulting moist powder is dried at 70° C.

[0104] ABS Graft Polymer 3 (according to the invention)

[0105] 15 parts by weight (calculated as solids) of an anionicallyemulsified polybutadiene latex with a mean particle diameter d₅₀ of 185nm, a particle size distribution width d₉₀-d₁₀ of 51 nm and a gelcontent of 69 wt. % produced by free-radical seed polymerisation using apolybutadiene seed latex with a d₅₀ of 48 nm, 30 parts by weight(calculated as solids) of an anionically emulsified polybutadiene latexwith a mean particle diameter d₅₀ of 297 nm, a particle sizedistribution width d₉₀-d₁₀ of 77 nm and a gel content of 61 wt. %produced by free-radical seed polymerisation using a polybutadiene latexwith a d₅₀ value of 125 nm as seed latex, and 15 parts by weight(calculated as solids) of an anionically emulsified polybutadiene latexwith a mean particle diameter d₅₀ of 422 nm, a particle sizedistribution width d₉₀-d₁₀ of 63 nm and a gel content of 80 wt. %produced by free-radical seed polymerisation using a polybutadiene seedlatex with a d₅₀ value of 185 nm, are adjusted with water to a solidscontent of ca. 20 wt. %, heated to 55° C., following which 0.5 part byweight of potassium peroxodisulfate (dissolved in water) is added.

[0106] 40 parts by weight of a mixture of 73 wt. % of styrene, 27 wt. %of acrylonitrile and 0.12 parts by weight of tert.-dodecyl mercaptan areuniformly metered in within 5 hours, and in parallel to this 1 part byweight (calculated as solids) of the sodium salt of a resin acid mixture(Dresinate 731, dissolved in alkaline adjusted water) is metered in overa period of 5 hours. During the course of the 5 hours the reactiontemperature is raised from 55° C. to 80° C. After a post-reaction timeof 2 hours at 80° C. the graft latex is coagulated after adding ca. 1.0part by weight of a phenolic antioxidant, with a magnesiumsulfate/acetic acid mixture, and after washing with water the resultingmoist powder is dried at 70° C.

[0107] ABS Graft Polymer 4 (according to the invention)

[0108] 20 parts by weight (calculated as solids) of an anionicallyemulsified polybutadiene latex with a mean particle diameter d₅₀ of 185nm, a particle size distribution width d₉₀-d₁₀ of 51 nm and a gelcontent of 69 wt. % produced by free-radical seed polymerisation using apolybutadiene seed latex with a d₅₀ of 48 nm, 27.5 parts by weight(calculated as solids) of an anionically emulsified polybutadiene latexwith a mean particle diameter d₅₀ of 297 nm, a particle sizedistribution width d₉₀-d₁₀ of 77 nm and a gel content of 61 wt. %produced by free-radical seed polymerisation using a polybutadiene latexwith a d₅₀ value of 125 nm as seed latex, and 12.5 parts by weight(calculated as solids) of an anionically emulsified polybutadiene latexwith a mean particle diameter d₅₀ of 422 nm, a particle sizedistribution width d₉₀-d₁₀ of 63 nm and a gel content of 80 wt. %produced by free-radical seed polymerisation using a polybutadiene latexwith a d₅₀ value of 185 nm as seed latex, are adjusted with water to asolids content of ca. 20 wt. %, heated to 55° C., following which 0.5part by weight of potassium peroxodisulfate (dissolved in water) isadded.

[0109] 40 parts by weight of a mixture of 73 wt. % of styrene, 27 wt. %of acrylonitrile and 0.12 parts by weight of tert.-dodecyl mercaptan areuniformly metered in within 5 hours, and in parallel to this 1 part byweight (calculated as solids) of the sodium salt of a resin acid mixture(Dresinate 731, dissolved in alkaline adjusted water) is metered in overa period of 5 hours. During the course of the 5 hours the reactiontemperature is raised from 55° C. to 80° C. After a post-reaction timeof 2 hours at 80° C. the graft latex is coagulated after adding ca. 1.0part by weight of a phenolic antioxidant, with a magnesiumsulfate/acetic acid mixture, and after washing with water the resultingmoist powder is dried at 70° C.

[0110] ABS Graft Polymer 5 (according to the invention)

[0111] 17.5 parts by weight (calculated as solids) of an anionicallyemulsified polybutadiene latex with a mean particle diameter d₅₀ of 189nm, a particle size distribution width d₉₀-d₁₀ of 50 nm and a gelcontent of 76 wt. % produced by free-radical seed polymerisation using apolybutadiene seed latex with a d₅₀ of 46 nm, 35 parts by weight(calculated as solids) of an anionically emulsified polybutadiene latexwith a mean particle diameter d₅₀ of 285 nm, a particle sizedistribution width d₉₀-d₁₀ of 60 nm and a gel content of 67 wt. %produced by free-radical seed polymerisation using a polybutadiene latexwith a d₅₀ value of 119 nm as seed latex, and 17.5 parts by weight(calculated as solids) of an anionically emulsified polybutadiene latexwith a mean particle diameter d₅₀ of 399 nm, a particle sizedistribution width d₉₀-d₁₀ of 56 nm and a gel content of 85 wt. %produced by free-radical seed polymerisation using a polybutadiene latexwith a d₅₀ value of 189 nm as seed latex, are adjusted with water to asolids content of ca. 20 wt. %, heated to 55° C., following which 0.5part by weight of potassium peroxodisulfate (dissolved in water) isadded.

[0112] 30 parts by weight of a mixture of 73 wt. % of styrene, 27 wt. %of acrylonitrile and 0.1 part by weight of tert.-dodecyl mercaptan arethen uniformly added within 6 hours. The further production is carriedout as described in ABS graft polymer 1.

[0113] ABS Graft Polymer 6 (according to the invention)

[0114] 15 parts by weight (calculated as solids) of an anionicallyemulsified butadiene/styrene (90:10) copolymer latex with a meanparticle diameter d₅₀ of 176 nm, a particle size distribution widthd₉₀-d₁₀ of 48 nm and a gel content of 60 wt. %, produced by free-radicalseed polymerisation using a butadiene/styrene (90:10) copolymer latexwith a d₅₀ value of 39 nm as seed latex, 30 parts by weight (calculatedas solids) of an anionically emulsified polybutadiene with a meanparticle diameter d₅₀ of 285 nm, a particle size distribution widthd₉₀-d₁₀ of 60 nm and a gel content of 67 wt. % produced by free-radicalseed polymerisation using a polybutadiene latex with a d₅₀ value of 119nm as seed latex, and 15 parts by weight (calculated as solids) of ananionically emulsified butadiene/styrene (90:10) copolymer latex with amean particle diameter d₅₀ of 391 nm, a particle size distribution widthd₉₀-d₁₀ of 75 nm and a gel content of 74 wt. % produced by free-radicalseed polymerisation using a butadiene/styrene (90:10) copolymer latexwith a d₅₀ value of 176 nm as seed latex, are adjusted with water to asolids content of ca. 20 wt. %, heated to 55° C., followed which 0.5part by weight of potassium peroxodisulfate (dissolved in water) isadded.

[0115] 40 parts by weight of a mixture of 73 wt. % of styrene and 27 wt.% of acrylonitrile are then uniformly metered in within 5 hours, 0.12part by weight of tert.-dodecyl mercaptan being uniformly metered inwithin the first 4 hours. In parallel to this 1 part by weight(calculated as solids) of the sodium salt of a resin acid mixture(Dresinate 731, Abieta Chemie GmbH, Gersthofen, Germany, dissolved inalkaline adjusted water) is metered in over a period of 5 hours. Duringthe course of the 5 hours the reaction temperature is raised from 55° C.to 80° C. The further production is carried out as described in the ABSgraft polymer 1.

[0116] ABS Graft Polymer 7 (comparison material, not according to theinvention)

[0117] The production described under “ABS graft polymer 1” is repeated,wherein a polybutadiene latex with a mean particle diameter d₅₀ of 183nm, a particle size distribution width d₉₀-d₁₀ of 103 nm and a gelcontent of 79 wt. %, produced without using seed latex was used asfinely particulate rubber component, a polybutadiene latex with a meanparticle diameter d₅₀ of 305 nm, a particle size distribution widthd₉₀-d₁₀ of 108 nm and a gel content of 55 wt. % was used as meanparticulate rubber component, and a polybutadiene latex with a meanparticle diameter d₅₀ of 423 nm, a particle size distribution widthd₉₀-d₁₀ of 99 nm and a gel content of 78 wt. % produced without usingseed latex was used as coarsely particulate rubber component.

[0118] ABS graft polymer 8 (comparison material, not according to theinvention)

[0119] The production described under “ABS graft polymer 1” is repeated,wherein instead of the polybutadiene latex mixture there were used 60parts by weight (calculated as solids) of a polybutadiene latex with amean particle diameter d₅₀ of 131 nm, a particle size distribution widthd₉₀-d₁₀ of 76 nm and a gel content of 88 wt. % produced without usingseed latex.

[0120] ABS graft polymer 9 (comparison material, not according to theinvention)

[0121] The production described under “ABS graft polymer 1” is repeated,except that instead of the polybutadiene latex mixture there were used60 parts by weight (calculated as solids) of a polybutadiene latex witha mean particle diameter d₅₀ of 423 nm, a particle size distributionwidth d₉₀-d₁₀ of 99 nm and a gel content of 78 wt. % produced withoutusing seed latex.

[0122] Resin Component 1

[0123] Statistical styrene/acrylonitrile copolymer(styrene/acrylonitrile weight ratio 72:28) with a {overscore (M)}_(w) ofca. 85,000 and {overscore (M)}_(w)/{overscore (M)}_(n)−1≦2 obtained byfree-radical solution polymerisation.

[0124] Resin Component 2

[0125] Statistical styrene/acrylonitrile copolymer(styrene:acrylonitrile weight ratio 72:28) with a {overscore (M)}_(w) ofca. 115,000 and {overscore (M)}_(w)/{overscore (M)}_(n)1≦2 obtained byfree-radical solution polymerisation.

[0126] Moulding Compositions

[0127] The aforedescribed polymer components are mixed in theproportions given in Table 1 together with 2 parts by weight ofethylenediamine bisstearyl amide and 0.1 part by weight of a siliconeoil in an internal kneader, and after granulation are processed intotest pieces and into a flat sheet (in order to evaluate the surface).

[0128] The following data are obtained:

[0129] notched impact strength at room temperature (a_(k)) according toISO 180/1A (unit: kJ/m²), thermoplastic flowability (MVI) according toDIN 53735U (unit: cm³/10 min) and surface gloss according to DIN 67530at a reflecting angle of 20° (reflectometer value).

[0130] It is clear from the Examples (test data see Table 2) that themoulding compositions according to the invention are characterised by acombination of high toughness values, very good processability andextremely high gloss values. TABLE 1 Compositions of the mouldingcompositions ABS ABS ABS ABS ABS ABS ABS ABS ABS Graft Graft Graft GraftGraft Graft Graft Graft Graft Resin Resin Polymer Polymer PolymerPolymer Polymer Polymer Polymer Polymer Polymer Component Component 1 23 4 5 6 7 8 9 1 2 (parts (parts (parts (parts (parts (parts (parts(parts (parts (parts (parts Example by wt.) by wt.) by wt.) by wt.) bywt.) by wt.) by wt.) by wt.) by wt.) by wt.) by wt.)  1 27 — — — — — — —— 73 —  2 — 27 — — — — — — — 73 —  3 — — 27 — — — — — — 73 —  4 — — — 27— — — — — 73 —  5 — — — — 23.2 — — — — 76.8 —  6 — — — — — 27 — — — 73 — 7(Comparison) — — — — — — 27 — — 73 —  8(Comparison) — — — — — — — 13.513.5 73 —  9 40 — — — — — — — — — 60 10 — — 40 — — — — — — — 6011(Comparison) — — — — — — — — 40   — 60

[0131] TABLE 2 Test data of the moulding compositions Example a_(k)(kJ/m²) MVI (cm³/10 min) Degree of Gloss  1 18.1 39.9 98  2 19.2 39.0 96 3 19.4 39.1 96  4 17.1 40.2 96  5 19.4 38.3 95  6 18.6 40.1 96  7(Comparison) 19.1 36.2 92  8 (Comparison) 18.3 35.2 93  9 32.0 8.1 95 1030.8 8.5 95 11 (Comparison) 30.3 7.6 88

1. Polymer compositions containing I) a graft rubber polymer that can beobtained by emulsion polymerisation of styrene and acrylonitrile in aweight ratio of 95:5 to 50:50, wherein styrene and/or acrylonitrile canbe wholly or partially replaced by α-methylstyrene, methyl methacrylateor N-phenylmaleimide or mixtures thereof, in the presence of a mixtureof a butadiene polymer latex (A) with a mean particle diameter d₅₀≦250nm and a particle size distribution width (measured as d₉₀-d₁₀ from theintegral particle size distribution) of 20 to 80 nm and a gel content of30 to 95 wt. %, a butadiene polymer latex (B) with a mean particlediameter d₅₀>250 to 350 nm, a particle size distribution width (measuredas d₉₀-d₁₀ from the integral particle size distribution) of 30 to 100 nmand a gel content of 30 to 80 wt. %, and a butadiene polymer latex (C)with a mean particle diameter d₅₀>350 nm, a particle size distributionwidth (measured as d₉₀-d₁₀ from the integral particle size distribution)of 40 to 150 nm, and a gel content of 50 to 95 wt. %, wherein thebutadiene polymer latices in each case contain 0 to 50 wt. % of afurther vinyl monomer incorporated by copolymerisation and wherein themass ratio of the graft monomers that are used to the butadiene polymersthat are used is 5:95 to 70:30, and II) at least one rubber-freecopolymer of styrene and acrylonitrile in a weight ratio of 95:5 to50:50, wherein styrene and/or acrylonitrile can be wholly or partiallyreplaced by α-methylstyrene, methyl methacrylate or N-phenylmaleimide ormixtures thereof, wherein at least one latex selected from the butadienepolymer latices (A), (B) and (C) is produced by seed polymerisation. 2.Polymer compositions according to claim 1, wherein the butadiene polymerlatex (A) has a mean particle diameter d₅₀ of 100 to 240 nm, a particlesize distribution width (measured as d₉₀-d₁₀ from the integral particlesize distribution) of 30 to 60 nm and a gel content of 40 to 90 wt. %,the butadiene polymer latex (B) has a mean particle diameter d₅₀ of 260to 340 nm, a particle size distribution width (measured as d₉₀-d₁₀ fromthe integral particle size distribution) of 40 to 80 nm, and a gelcontent of 40 to 75 wt. %, and the butadiene polymer latex (C) has amean particle diameter d₅₀ of 360 to 450 nm, a particle sizedistribution width (measured as d₉₀-d₁₀ from the integral particle sizedistribution) of 50 to 100 nm and a gel content of 55 to 90 wt. %. 3.Polymer compositions according to claims 1 and 2, wherein the butadienepolymer latex (A) has a mean particle diameter d₅₀ of 130 to 230 nm anda particle size distribution width (measured as d₉₀-d₁₀ from theintegral particle size distribution) of 30 to 60 nm and a gel content of50 to 85 wt. %, the butadiene polymer latex (B) has a mean particlediameter d₅₀ of 270 to 320 nm, a particle size distribution width(measured as d₉₀-d₁₀ from the integral particle size distribution) of 40to 80 nm, and a gel content of 45 to 70 wt. %, and the butadiene polymerlatex (C) has a mean particle diameter d₅₀ of 375 to 430 nm, a particlesize distribution width (measured as d₉₀-d₁₀ from the integral particlesize distribution) of 50 to 100 nm and a gel content of 60 to 85 wt. %.4. Polymer composition according to any of claims 1 to 3, wherein atleast two latices selected from the butadiene polymer latices (A), (B)and (C), are produced by seed polymerisation.
 5. Polymer compositionaccording to claim 4, wherein all three butadiene polymer latices (A),(B) and (C), are produced by seed polymerisation.
 6. Process forproducing a polymer composition, wherein a graft rubber polymer that canbe obtained by emulsion polymerisation of styrene and acrylonitrile in aweight ratio of 95:5 to 50:50, wherein styrene and/or acrylonitrile canbe wholly or partially replaced by α-methylstyrene, methyl methacrylateor N-phenylmaleimide or mixtures thereof, is produced in the presence ofa mixture of a butadiene polymer latex (A) with a mean particle diameterd₅₀≦250 nm and a particle size distribution width (measured as d₉₀-d₁₀from the integral particle size distribution) of 20 to 80 nm and a gelcontent of 30 to 95 wt. %, a butadiene polymer latex (B) with a meanparticle diameter d₅₀>250 to 350 nm, a particle size distribution width(measured as d₉₀-d₁₀ from the integral particle size distribution) of 30to 100 nm, and a gel content of 30 to 80 wt. %, and a butadiene polymerlatex (C) with a mean particle diameter d₅₀>350 nm, a particle sizedistribution width (measured as d₉₀-d₁₀ from the integral particle sizedistribution) of 40 to 150 nm, and a gel content of 50 to 95 wt. %,using at least one latex produced by seed polymerisation and selectedfrom the butadiene polymer latices (A),(B) and (C), wherein thebutadiene polymer latices in each case contain 0 to 50 wt. % of afurther vinyl monomer incorporated by copolymerisation and wherein theweight ratio of graft polymers that are used to the butadiene polymersthat are used is 5:95 to 70:30, and the graft polymer is mixed with atleast one rubber-free copolymer of styrene and acrylonitrile in a weightratio of 95:5 to 50:50, wherein styrene and/or acrylonitrile may bepartially or wholly replaced by alpha-styrene, methyl methacrylate orN-phenylmaleimide or mixtures thereof.
 7. Polymer compositions accordingto any of claims 1 to 6, containing in addition at least one resinselected from an aromatic polycarbonate, aromatic polyester carbonate,polyester, polyamide or mixtures thereof.
 8. Polymer compositionsaccording to any of claims 1 to 7, characterised in that in theproduction of the graft rubber polymers the monomers are added in such away that 55 to 90 wt. % of all the monomers used in the graftpolymerisation are metered in within the first half of the overall timefor metering in the monomers, and the remaining proportion of themonomers is metered in within the second half of the overall time formetering in the monomers.
 9. Polymer compositions according to any ofclaims 1 to 8, characterised in that in the production of the graftrubber polymers the temperature difference between the start and end ofthe grafting reaction is at least 15° C.
 10. Process for producingpolymer compositions according to any of claims 1 to 9, characterised inthat the components I) and II) are mixed and are then compounded andextruded at elevated temperature.
 11. Use of the polymer compositionsaccording to any of claims 1 to 10 for producing moulded parts. 12.Moulded parts that can be obtained from polymer compositions accordingto any of claims 1 to
 10. 13. Graft rubber polymer that can be obtainedby emulsion polymerisation of styrene and acrilonitrile in a weightratio of 95:5 to 50:50, wherein styrene and/or acrylonitrile can bewholly or partially replaced by α-methylstyrene, methyl methacrylate orN-phenylmaleimide or mixtures thereof, in the presence of a mixture of abutadiene polymer latex (A) with a mean particle diameter d₅₀≦250 nm anda particle size distribution width (measured as d₉₀-d₁₀ from theintegral particle size distribution) of 20 to 80 nm, and a gel contentof 30 to 95 wt. %, a butadiene polymer latex (B) with a mean particlediameter d₅₀>250 to 350 nm, a particle size distribution width (measuredas d₉₀-d₁₀ from the integral particle size distribution) of 30 to 100nm, and a gel content of 30 to 80 wt. %, and a butadiene polymer latex(C) with a mean particle diameter d₅₀>350 nm, a particle sizedistribution width (measured as d₉₀-d₁₀ from the integral particle sizedistribution) of 40 to 150 nm, and a gel content of 50 to 95 wt. %,wherein the butadiene polymer latices in each case contain 0 to 50 wt. %of a further vinyl monomer incorporated by copolymerisation, wherein theweight ratio of the graft monomers that are used to the butadienepolymers latices that are used is 5:95 to 70:30, and wherein at leastone latex selected from the butadiene polymer latices (A), (B) and (C)is produced by seed polymerisation.